Acoustics is the science that deals with the study and technology of sound. Generally the study of acoustics includes the generation, propagation, control and reception of mechanical waves and vibrations, their interaction with materials and their effects.

Noise is sometimes defined as unwanted or excessive sound. Depending upon the circumstances – noise can give rise to nuisance and disturbance (environmental or community noise). Occupational exposure to noise (workplace noise) can cause noise induced hearing loss (NIHL) and tinnitus. Excessive noise at work has also been identified as a potential factor in workplace accidents.

When a surface or structure rapidly oscillates backwards or forwards the motion is referred to as vibration. The rate at which the occillation (repeated movement) occurs is known as the frequency of the vibration and this is measured in cycles per second or hertz (Hz). Sound and vibration are closely related and sound can be considered as pressure waves or air vibrations which are audible. These waves are generated by vibrating structures (e.g., loudspeakers or human vocal cords) and these pressure waves can also induce the vibration of structures. Many activities (e.g., heavy traffic, quarry blasts, etc.) have the potential to give rise to sound and vibration emissions.

Vibration within buildings is generally assessed in terms of its acceptability to the human occupants. In most instances there is a need to distinguish between the perceived risk and the actual risk and invariability we assess the level of vibration against specified criteria. Occasionally large amplitude shock and vibrations will need to be assessed with respect to their potential effects on the buildings and structures, as opposed to the building occupants.